As a technique on a condensing dehumidifier capable of improving drying efficiency, Korean Patent No. 10-0892601 (hereinafter, referred to as “the prior art”) is disclosed, entitled “Moisture removing apparatus of plastic material using condensing phenomenon by thermoelectric element or thermal medium,” filed and registered by the applicant (Korea Electric Industry Company).
The prior art is constituted by a source material storage hopper configured to store a plastic material; an air supply pipe having one end installed in the source material storage hopper and the other end connected to an air heater; the air heater in which a heater having one end connected to the air supply pipe and the other end connected to a blower is installed; the blower having one end connected to the air heater and the other end connected to a condensing unit; the condensing unit in which a cooling coil having one end connected to the blower and the other end connected to an air cooler is installed; a cooling unit configured to circulate cooling water through the condensing unit; the air cooler having one end connected to the condensing unit and the other end connected to an air filter; and the air filter having one end connected to the air cooler and the other end connected to an upper portion of the source material storage hopper, wherein the cooling unit is constituted by a cooling fan, a compressor, and a coolant circulation pipe.
According to the prior art, the air discharged after drying the plastic material is condensed, the air from which moisture is removed is heated again, and then, the air is resupplied to the source material storage hopper, thereby more effectively drying the plastic material.